QUALITY IMPROVEMENT OF 'SEOUL' CELERY BY SELENIUM IN THE NUTRIENT SOLUTION CULTURE

Abstract

Our study centred on the uptake of sodium selenate and sodium selenite by vegetables and the accumulated contents of selenium in vegetables in nutrient solution culture. Effects of selenate and selenite ion on the growth and internal quality of celery were also studied. Accumulated Se contents in 'Seoul' celery increased with increasing rates of Se added to the nutrient solution in both sodium selenate and sodium selenite treatments. However, when Na 2 SeO 4 and Na 2 SeO 3 treatments were compared more Se was found to have accumulated in leaves and petioles by the Na 2 SeO 4 treatment. The celery leaves accumulated higher amounts of Se than petioles at the same concentrations of Na 2 SeO 4 and Na 2 SeO 3 . Even though growth was not severely affected by Se concentrations of up to 6 mg.L -1 , Se contents were very high (57.3 mg Se.kg -1 dry matter). Selenite uptake by plants exhibited similar patterns, though overall accumulated contents were lower than for selenate treatments. In the case of selenate treatments, total vitamin C contents gradually increased with the increase of selenate concentrations in both leaves and petioles. Nitrate and protein contents of edible parts (petioles) decreased with the increase of selenate and selenite concentrations. Chlorophyll contents in leaves increased in 2 and 4 mg.L -1 treatments. These results suggest that selenate treatments of up to 4 mg.L -1 did not adversely affect celery growth, and that treatments below 4 mg.L -1 of sodium selenate or of sodium selenite to celery can be recommended.